In the wood stove industry, before installing wood stoves, it is common place to use precast non-combustible panels, consisting mainly of cement as the immediate supporting structure, and often also as a nearby upstanding panel serving as a nearby wall structure. In the past these heavy precast non-combustible panels were essentially handled by hand and by using inadequate carts. When being delivered to the marketplace, or to a home, these heavy panels must be passed through person sized doorways, and over thresholds, and maneuvered through narrow passageways. Also their handling at distributors' facilities, and their handling at the manufacturer's facilities is oftentimes equally inconvenient. Persons moving these members, especially the non combustible panels, are often hurt, many of them incurring back injuries.
In searching the marketplace and also information sources, such as United States patents, no carts were found which were considered suitable. Of many patents reviewed, some were noted as directed to carrying dwelling construction materials. Mr. Aksel F. Grymer in his U.S. Pat. No. 3,003,788 of 1961 disclosed his glazier's truck for moving plates of glass to required locations in a building under construction. His planar rectangular platform has removable longitudinal side vertical supports used in positioning the glass plates on their edge and at an angle. Two larger diameter transversely spaced non castering wheels are secured underneath the planar rectangular platform, at one end, and two smaller diameter castering wheels are secured underneath this platform at the other end and positioned, so this platform remains horizontal on a level surface.
Mr. Stephen W. Bigney in his U.S. Pat. No. 3,841,651 of 1974, disclosed his wheel mounted, support platform, hand truck for moving building sheet material, such as plywood and drywall at a work site. His comparatively narrow elongated rectangular support platform has a longitudinal side vertical support secured at places which are aligned along one side of the support platform. Two large wheels on a transverse axle are secured to the central section of the support platform. Portions of each of these two large wheels are higher, during their rotation and while standing, than the support platform. The drywall and/or plywood panels are closely arranged adjacent to the longitudinal side vertical support, being kept essentially vertical. They are so held in his edge supported vertical position by a top horizontal hook selectably vertically positioned on the longitudinal side vertical support. There are secondary wheels of smaller diameter which do not touch the ground nor the floor, when the support platform remains level. However when the support platform is not is use, or when it is in use and a threshold of a doorway is being crossed, then one of these secondary wheels touches the ground or floor to compete a three wheel support of this support platform hand truck.
Mr. Tord M. Hellsten in his U.S. Pat. No. 4,488,733 disclosed his wheeled plate carrier, for transporting building boards. He provided an elongated base, supported, while at an angle, on one large wheel at its central section, and on respective small wheels at each end. The latter small wheels were on extended arms, making a three wheel support of this elongated narrow base. Once underway, however, the elongated narrow base became horizontal, and its perpendicular frame became upright. Also, when underway, generally only the large wheel was supporting the building boards. The perpendicular frame was equipped with a handle bar, and also a combined hook and strap subassembly used in holding the top edges of the building boards closely adjacent to the upright frame, so they remained closely positioned adjacent the upright frame throughout their then upright width.
In summary, although Mr. Grymer illustrated his glazier's truck, on which glass was carried into dwellings, while supported at an angle, and the sides of the truck were removable, he did not indicate a truck having larger wheels, which would be the only wheels supporting the load, if the support platform remained level. Mr. Bigney illustrated his very narrow hand truck which supported sheet material in a vertical position and he did indicate using larger wheels, which would be the only wheels supporting the load, if the support platform remained level. Mr. Hellsten illustrated his wheeled plate carrier, which supported building boards adjacent an upright support, which at rest was at an angle, and which underway was upright. The single large wheel and the two offset small wheels were all in contact with a floor, when the upright support was at an angle. However, only the single large wheel was in contact with a floor, when the upright support was vertical.
These products of Messrs. Grymer, Bigney and Hellsten, are recognized for their operational benefits. However, when the often larger, and heavier, and more irregular non combustible supports and non combustible panels, used with wood stoves, and wood stoves themselves, are to be transported, then another cart is needed.